Area meter

ABSTRACT

To synchronize the belt of a conveyor, a scanner, a fluorescent lamp, and an LED display unit of an area meter, the main AC power supply of the area meter drives the conveyor belt through a synchronous motor and supplies the same frequency of power to a phase locked loop. The phase locked loop provides synchronous pulses of higher frequencies to the scanning system, fluorescent lamp and LED display unit to maintain synchronism. The resolution of the measuring system is optimized when changes are made in the size of the area that is scanned by adjusting: (1) the lens of the scanner; (2) the rate of readout of the pulses from the scanner; and (3) the decimal place of the display unit. Travel from side to side of the belt is avoided by individually adjusting the ends of the pulleys until the belt runs true and an idler which lifts both bottom and top run of the belt when an object moves under it prevents slippage of the belt with respect to the rollers and the bite of the conveyor is adjustable.

This invention relates to area meters.

In the one class of area measuring device, the object to be measured anda sensor are moved with respect to each other, with the sensorgenerating pulses proportional to the area of the object that is beingmeasured. A counter counts the pulses and indicates the area. Certaintypes of this class of area measuring device include a conveyortransport system that moves the object past the scanner.

In a prior art type of area measuring device of this class, the objectto be measured is scanned by a light beam which sweeps across the objectand the light not blocked by the object is collected by a photocell.During the time of each scan that light is blocked by the object, pulsesare counted. The pulses are generated in a photocell by light whichpasses through apertures in a disc, driven by gears in synchronism withthe conveyor belt. The pulses are counted to indicate the area.

The belts of the prior art conveyor systems have a tendency to travelfrom one side of the rollers to the other with time and have difficultyin handling thick objects because the upward movement of the bottom runof the upper belt loosens the belt about the drive roller, thus causingslippage of the upper belt.

The prior art apparatuses have several disadvantages such as: (1) theyare expensive because of the mechanical coupling and mechanical methodsfor generating pulses; (2) because the system is designed to measureobjects of substantially the same width, resolution is lost for smallerobjects; (3) they do not easily accept thick objects; (4) they are notsusceptible to continuous trouble free running because the belt movesfrom one side to the other; (5) they are excessively sensitive tobackground light and thus must be enclosed; and (6) they tend to beinaccurate in measuring edges.

Accordingly, it is an object of the invention to provide a novel areameasuring device.

It is a still further object of the invention to provide a novel methodand apparatus for scanning an object in one direction in synchronismwith its motion in another direction.

It is a still further object of the invention to provide an improvedarea measuring system.

It is a still further object of the invention to provide an improvedconveyor system.

It is a still further object of the invention to provide a conveyorsystem in which the tendency for the belts to travel in the direction ofthe longitudinal axis of the rollers is reduced.

It is a still further object of the invention to provide a conveyorsystem in which the bottom and top runs of the belts of the conveyorsystem are maintained in substantially equal tension when thick objectsare passed between the belts of the conveyor system.

It is a still further object of the invention to provide an areameasuring system which may be easily adjusted to measure differentamounts of area with good resolution.

In accordance with the above and further objects of the invention, anarea meter includes a conveyor having top and bottom endless belts and afeed station for feeding objects to be measured between the top run ofthe bottom belt and the bottom run of the top belt, which top and bottomruns move in the same direction to carry the object thereinbetween. Therollers of the conveyor are adjustable on each end so that the tendencyof the belts to creep on the rollers in the direction of thelongitudinal axis of the rollers is reduced. The tendencies arecorrected by adjusting the individual ends of the rollers until the beltruns true.

To maintain downward pressure from the top belt against the bottom belt,an idler is pivotally mounted between the top and bottom runs of the topbelt. This idler has bottom and top rollers with the bottom roller beingin contact with the bottom run and the top roller being in contact withthe top run. The two rollers of the idler are fixed in position witheach other and pivotable about a location removed from the rollers sothat a thick object, in lifting the bottom run lifts both the bottomroller and the top roller thus moving the top run upwardly to maintaintension in the top belt. The two rollers of the idler are positioned sothat these outer rims are spaced from each other a distance slightlygreater than the diameter of the conveyor rollers to permit curvature inthe upper or lower run of the top belt.

The belts are driven from a single synchronous motor which is geared tothe drive rollers of the system. The alternating current supply to thesynchronous motor is also applied as a reference frequency to a phaselocked loop that generates scanning frequencies and display frequencies.

The scanner includes a fluorescent lamp, driven from a sourcesynchronized with the phase locked loop so that it is pulsed to providevideo illumination at a controlled repetition rate. The light from thefluorescent lamp is focused by a mirror system onto a photocell arrayhaving sensors spaced two millimeters apart center to center. Thesensors are scanned by a clock system the start time of which issynchronized with the phase locked loop and generates a pulse forcounting for each of the light sensors which is shaded from thefluorescent light. These pulses are counted and displayed in unitsrepresenting the area of the object being scanned.

To start the fluorescent lamp, a start switch is provided which causescurrent to flow through a transformer that drives the lamp andfilaments. Upon breaking this circuit, the inductive field developed inthe transformer applies a high starting voltage across the fluorescentlamp and thereafter alternating drive potential is applied to the lampto keep it illuminated with an on and off cycle rate that issufficiently high to provide good video from the scanner.

The conveyor system can be adjusted for different sized objects by: (1)changing the lens on the scanner to focus smaller objects across a widerarea of the array; (2) adjusting the counter so that a different numberof pulses are counted for each sensing unit that is shaded by the objectfrom the fluorescent light; and (3) changing the decimal point of theLED display unit to provide a display of an appropriate number ofsignificant digits. With this approach, a scanning array provides goodresolution for smaller objects as well as good resolution for largerobjects. The bite of the conveyor is adjustable.

It can be understood from the above description that the area meter ofthis invention has the advantages of: (1) being easily adjustable toprevent travel of the belts from side to side on the rollers; (2) havingan idler which maintains tension on the belt of the conveyor system whena thick object is passed through the conveyor system; (3) beingadjustable to measure different sized objects with good resolution; and(4) being relatively inexpensive. Some reasons that it is inexpensiveare because it has an economical synchronizing system, an inexpensivesystem for starting the fluorescent lamps, standard camera lens and aninexpensive light source.

The above noted and other features of the invention will be betterunderstood from the following detailed description when considered withreference to the accompanying drawings in which:

FIG. 1 is a simplified, exploded perspective view of an area meter inaccordance with an embodiment of the invention;

FIG. 2 is a block diagram of the area meter in FIG. 1;

FIG. 3 is a block diagram of a portion of the area meter of FIG. 1;

FIG. 4 is a block diagram of another portion of the area meter of FIG.1;

FIG. 5 is a block diagram of still another portion of the area meter ofFIG. 1;

FIG. 6 is a logic diagram of still another portion of the area meter ofFIG. 1; and

FIG. 7 is a schematic circuit diagram of a portion of the area meter ofFIG. 1.

In FIG. 1, there is shown, in a simplified, exploded, perspective view,an area meter 10 having a feed station 12, a transport section 14, anindicating display 16, and a measuring system to be describedhereinafter. The measuring system includes a scanning sensor 18, afluorescent lamp 20, first, second, and third mirrors 23, 24, and 22,and certain control circuitry (not shown in FIG. 1). The feed station12, transport section 14, and measuring system are arranged so that theobject to be measured, which may be a leaf or the like, is fed from thefeed station 12 into the transport system 14 where it is carried pastthe measuring system for measurement. The area is displayed in thedisplay unit 16. The display unit 16 is shown on the opposite side ofthe area meter 10 from its location in the preferred embodiment forillustration.

To move objects such as leaves or the like past a measuring station fromthe feed station 12, the transport system 14 includes a top conveyorsection 26 and a bottom conveyor section 28, positioned to be in contactwith each other, although the exploded view in FIG. 1 shows themseparated.

The top conveyor section 26 includes a first roller 30, a second roller32, an idler assembly 34, and an endless transparent conveyor belt 36.The roller 32 is a drive roller driven by a pinion 39 and thetransparent belt 36 extends around both roller 30 and 32, with idlerassembly 34 being positioned between the top run and the bottom run ofthe belt 36. The rollers are cylinders, positioned horizontally, andhaving a diameter of approximately two inches to accommodate the idlerassembly 34 and a length of approximately 15 inches. The belt isapproximately 12 inches in width.

The idler assembly 34 includes first and second idler rollers 38 and 40rotatably mounted on their opposite ends to pivotable side plates 42 and44 for rotation thereon. The idler rollers 38 and 40 extend indirections parallel to the rollers 30 and 32 and have their outer rimsspaced from each other a distance greater than the diameter of theconveyor rollers 30 and 32 to permit curvature in the top run or thebottom run of the conveyor belt 36. The side plates 42 and 44 aremounted together by a flat support 46 at one end and form an assemblywhich pivots with respect to the outer frame at points 50 and 52. Aportion of the outer frame is shown at 54 but the entire main porton ofthe framing members encasing the conveyor have been omitted from FIG. 1to show the operating parts of the area meter.

The entire assembly 34 pivots about the points 50 and 52 when an objectpassing between conveyor sections 26 and 28 lifts the roller 40 so thatthe top run of the conveyor belt 36 is lifted along with its bottom run,thus shifting the normal curvature in the bottom run to an uppercurvature in the top run and maintaining tension in the belt.

The bottom conveyor section 28 includes rollers 56 and 58 and atransparent belt 60 corresponding to the structure and cooperating withthe rollers 30 and 32 and the transparent belt 36 of the top conveyor26. The top run of the belt 60 is positioned in contact with the bottomrun of the belt 36. The roller 58 is the drive roller and is driven fromthe same source as the roller 32. In one embodiment, the roller 56 isadjustable in position upwardly toward roller 30 to adjust the bite or aseparate roller can be used for this purpose.

To drive rollers 32 and 58, a drive motor 64 has its output shaftconnected to roller 58 and to spur gear 62 for rotation therewith. Thegear 62 engages a pinion 39 so that the roller 32 of the top conveyorsection 26 and the roller 58 of the bottom conveyor section 28 are bothdriven in synchronism with each other by the drive motor 64 to move anitem along the transport path between the conveyor belts 36 and 60. Ofcourse, the ratio between the two gears and the diameters of the rollersare selected so that the same linear speed is provided by the conveyorbelts 60 and 36 and thus motion of one with respect to the other isavoided.

An idler roller 69 is mounted beneath the top run of the conveyor belt60 opposite to the roller 40 so that the top run of the conveyor belt 60and the bottom run of the conveyor belt 36 are pressed between the idlerroller 69 and the idler roller 40, with the idler roller 40 being liftedby items passing therebetween against the weight of the assembly 34 andlifting the top run of conveyor belt 36 to avoid slack on the belt fromrelease of weight of idler assembly 34.

Each of the rollers 30, 32, 56 and 58 is mounted at its opposite ends tothe area meter cabinet 54 by a different one of eight journal plates66A-66H, four of which 66A, 66B, 66E and 66F are adjustable. Each of theadjustable plates 66A, 66B, 66E and 66F is identical and only one, 66A,will be described herein.

The adjustable journal plate 66A is an aluminum parallelopiped having acylindrical bearing bore 68 into which a shaft of a roller is journaledfor rotation therein and a horizontal slot 72 adapted to receive a bolt70 for mounting the plate 66A to the area meter cabinet 54. The slot 72is sufficiently wide to receive the shank of the bolt 70 andsufficiently long so that the bolt 70 can rest in different locationswithin the plate 66A permitting adjustment of the position of the platewith respect to cabinet 54 into which the bolt extends. With thisstructure, each end of the rollers may be independently adjusted. InFIG. 1 each of the visible plates 66A, 66D, 66E and 66G is shown withthe same structures, but of course only the plates 66A, 66B, 66E and 66Fneed be adjustable.

The independent adjustability of the ends of the rollers permits thebelts to be loosened by moving both ends of a roller toward the otherroller or permits angular adjustment of an individual roller. Theangular adjustment of an individual roller changes the manner in whichthe belt tracks on that roller so that it may be kept centered.

The fluorescent lamp 20 of the measuring system is positioned betweenthe upper and lower runs of the transparent belt 36 above thetransparent belt 60 to shine light downwardly in the path of the objectto be measured. The mirror 23 is positioned to receive the light whichforms the image of the object between it and the lamp 20 and to reflectthis light to the mirror 24. The mirror 24 is positioned to receive thislight and to reflect it to mirror 22. The mirror 22 and sensor 18 arepositioned so that the lens of the sensor 18 is focused upon the imageof the object formed by mirror 22.

In the preferred embodiment, the sensor 18 is a solid-state line scannerincluding arrays of monolithic self-scanning linear photodiodes. Thearrays consist of a row of silicon photodiodes, with an associatedstorage capacitance which integrates current and a multiplex switch forperiodic readout by way of an integrating shift-register scanningcircuit. Such devices are sold under the trade name RETICON by ReticonCorporation, 910 Benicia Ave., Sunnyvale, California. Of course, othertypes of scanners may be used such as silicon tubes, CCD arrays and thelike.

The drive motor 64, sensor 18, and fluorescent lamp 20 areinterconnected so that, for each increment of distance that the conveyorbelts 60 and 36 are moved by the drive motor 64, the lamp 20 pulses asufficient number of times to provide good video signals. The image ofthe object being moved by the belts is focused on the sensor 18, whichscans along the line of the image at fixed increments of motion of theobject to determine the width of the object for that increment ofmotion. The width for each increment is added so as to provide a measureof the area of the object.

The frequency of line scans (number of complete scans each second) canbe adjusted with respect to the number of pulses provided by the drivemotor 64 as it turns the conveyor belts 36 and 60 to provide differentresolutions. Moreover, the resolution may be changed by changing thesize of the image of the object on the sensor. For example, objects maybe scanned at a higher frequency with the same belt speed or the beltspeed may be slowed to increase the resolution. Also, resolution may beincreased for narrow objects (distance in a direction perpendicular todirection of motion) by enlarging the image of the object to make use ofthe full number of photodiodes in a line of the sensor 18. A constantcorrection may be necessary to provide conventional units of measurementas an output when changes are made.

In the preferred embodiment, two different scan frequencies are used fortwo different width classifications, which scan frequencies are: (1) onescan for each one mil of linear movement; and (2) three scans for eachone mil of linear movement of the conveyor belts 36 and 60. One scanacross the Reticon sensor in the preferred embodiment provides 256elements on two mil centers. For simplicity in circuitry and improvedaccuracy, the single scan effect is obtained with scans which areaveraged and used as one scan.

To display the area measurement, the display 16 provides a readout of anumber corresponding to the integral of the incremental areameasurements by the sensor 18. The decimal point is adjustableelectronically to compensate for the smaller or larger objects toaccommodate different resolutions of measurement.

To feed objects to the transport system for measurement, the feedstation 12 includes a platform 76. The platform 76 includes two guides78 and 80 which are parallel to each other and extend in the directionof the transport path. The guides accommodate between them, the objectwhich is to be measured, as it is fed into the bite from between theguides. One plate is provided in the preferred embodiment having guides25.4 centimeters (10 inches) apart. This display 16 provides two digitsafter the decimal point. In another embodiment, a plate having guides7.62 centimeters (3 inches) apart is substituted to measure smallerobjects and the display 16 is adjusted to read 3 digits after thedecimal point.

Before operating the area meter, several adjustments are made, such asadjustments in: (1) the location of the rollers 56 and 30; (2) thedecimal point of the display 16; (3) the effective scan rate; (4) thelens of the sensor 18; and (5) the distance apart of the guides 78 and80.

To adjust the rollers 56 and 30, the bolt 70 which extends through theslot 72 is loosened and the rollers moved until the belts 36 and 60 aretight. The conveyor may be run at this time to see if the belts creep toone side or the other. If they do, the bolt on one side of theadjustable roller having the creep is loosened and the roller moved atan angle and the bolt re-tightened until the belt does not creep.

If small items are to be measured, a guide plate having guides 7.62centimeters (3 inches) apart is inserted in the feed station 12 and iflarger items are to be measured, a guide plate having guides 25.4centimeters (10 inches) apart is inserted in the guide station. The lens19 for the sensor 18 is a replaceable means and is selected so the imageis focused across a large portion of the sensor. This also requires inthe preferred embodiment a minor change in the position of the sensor18, as well as a lens change to obtain proper focusing.

Since the magnification of the image of the object and the scan rate aredifferent for small objects from the magnification and the scan rate forlarge objects being measured, the display 16 must also be adjusted sothat in the preferred embodiment, there are three significant decimalplaces to the right of the decimal point for small objects wherescanning is across a 7.62 centimeter distance and two where scanning isacross a 25.4 centimeter distance on the conveyor because of the changein resolution.

In operation, the object to be measured is carried by the transportsection 14 past the measuring system, where its image is scanned and itsarea read out on the display 16.

To carry an object through the transport section 14, the object is fedbetween the guides 78 and 80 of the feed station 12 into the bite of thebelts 60 and 36. Small items are fed on a support plate having theguides 78 and 80, 7.62 centimeters apart and large items are fed onto asupport plate having the guides 78 and 80, 25.4 centimeters apart. Thetwo different sizes of support plates are substitutable onto the feedstation 12.

The roller 30 is driven in a counter-clockwise direction (FIG. 1) andthe roller 56 is driven in a clockwise direction so that the conveyorbelts 60 and 36 grasp the item in the bite and move it securely alongbetween the belts without slippage. As the item is carried past thefluorescent lamp 20, its image is projected onto the sensor 18 where itis scanned. After being measured, it leaves the belts beyond the rollers58 and 32. The roller 32 drives the conveyor belt 36 and the roller 58drives the conveyor belt 60. Rotational force is applied to theserollers by the synchronous drive motor 64 which drives the spur gear 62through a motor output gear in a clockwise direction. The spur gear 62meshes with the pinion 39 to drive the roller 32 in a counter-clockwisedirection.

If the object is large, it lifts the idler pulley 40 as it passesbetween the idler pulley 40 and the idler roller 69, with the idlerassembly 34 pivoting about the pivot points 50 and 52. As the idlerassembly 34 is moved upwardly, the idler roller 38 lifts the top run ofthe conveyor belt 36 so that both the top run and the bottom run moveupwardly to maintain proper tension and permit the object to passbetween the belts. The idler assembly 34 also exerts force downwardly tohold the belts 36 and 60 together.

To form an image of the object as it passes the fluorescent lamp 20,light from the lamp is blocked by the object to form an image indicatedby a pattern of light impinging on mirror 23, which is located beneaththe transport section 14. The fluorescent lamp receives a square wave ACpotential which causes it to be illuminated practically continuously toprovide a good video signal. This light is reflected to the mirror 24which reflects it to the mirror 22, which reflects it to the scanner 18.The lens of the scanner 18 is selected to project a 7.62 centimeterimage directly across the sensing element for small items or a 25.4centimeter line across the scanning element for large objects.

To scan the image focused by the lens of the sensor 18 onto the sensingarray, the entire array of sensing elements is scanned at a rate fourtimes the line frequency (generally 240 scans per second). The 1millimeter spots in a line which are darkened are counted by the display16 and the light spots are not, resulting in the counting of a matrixcorresponding to the area of the object and the display of this area onthe display 16. The scan rate, the rate of pulses applied to thefluorescent lamp 20 and the belt drive are all maintained in synchronismwith the alternating current potential applied to the drive motor 64. Inthe preferred embodiment the belt is driven at 80 millimeters per secondalthough this rate can be altered, particularly if it is desirable toread out the area in dimensions other than centimeters on the display16.

In FIG. 2, there is shown a block diagram of the system which maintainsthe fluorescent lamp 20, the sensor 18, and the transport drive gear 62in synchronism. This system includes an AC source 82, the drive motor 64and a phase locked loop 86, with the AC source being at the samefrequency as the mains supply (60 hertz in the United States and 50hertz in certain other countries) and being electrically connected tothe drive motor 64 and to the phase locked loop 86.

The drive motor is a synchronous motor and is mechanically connected tothe transport drive gear 62 to drive the transport section 14 (FIG. 1)at a speed synchronous with the output of the AC source 82.

To keep the sensor 18 and fluorescent lamp 20 in synchronism with thetransport drive gear 62, the phase locked loop 86: (1) is electricallyconnected to the output of the AC source 82 by a conductor 88 throughwhich it receives, as a basic timing standard, the same frequencyelectrical power as that which drives the drive motor 64; (2) generates480 hertz (eight times mains frequency) electrical power and applies itto an output conductor 90; and (3) generates 240 hertz power (four timesmains frequency) and applies it to an output conductor 92. The phaselocked loop also generates 960 hertz power (sixteen times mainsfrequency) and applies it to an output conductor 94 to provide amultiplex frequency to the display 16.

The phase locked loop 86 serves as a means for generating basic timingpulses having a repetition rate proportional to the frequency of thealternating current from the AC source 82 and thus forms an intergralpart of a sensing means that generates pulses representing the width ofan object and a pulse means forming pulses at the rate at which theobject is moved.

To control the sensor 18 and the display 16: (1) a sensor input-outputcircuit 96 is electrically connected to conductor 92 through which itreceives the 240 hertz pulses and includes circuitry to read at asynchronous rate from the sensor 18 information concerning the area ofobjects as they pass through the transport section 14 (FIG. 4); and (2)the display 16 is electrically connected to the phase locked loop 86through conductor 94 to receive 960 hertz multiplex signals.

The sensor input-output circuit 96 includes circuitry that: (1) appliessignals to the sensor 18 through conductors 98A-98C to read informationfrom the sensor; (2) processes signals received from the sensor 18through conductors 100A and 100B; and (3) applies the processed signalto the display 16 through a conductor 102.

To enable the fluorescent lamp 20 to be illuminated and extinguished ata rate that provides a good video signal for measuring area, afluorescent lamp drive circuit 104 is electrically connected to theoutput of the conductor 90 from which it receives 480 hertz pulses. Thefluorescent lamp drive circuit 104 generates a high voltage pulse forapplication to the fluorescent lamp 20 through a conductor 106 to startthe fluorescent lamp, and thereafter, maintains the rate at which thelamp is illuminated in synchronism with the 480 hertz pulses applied tothe fluorescent lamp drive circuit 104 through conductor 90.

In FIG. 3, there is shown a block diagram of the phase locked loopcircuit 86 having VCO 108, first, second, and third dividers 110, 112,and 114 respectively, a comparator 116 and a low pass filter 119. TheVCO 108 has its output conductor electrically connected to conductor 94to provide 960 hertz pulses thereto and to divider 110 which dividesthese pulses by two and provides 480 hertz pulses to the conductor 90.Divider 112 has input connected to conductor 90 to receive 480 hertzpulses, which it divides by two, and thus applies 240 hertz pulses tooutput conductor 92 and to the input of the divider 114. Divider 114divides these pulses by four and applies 60 hertz pulses to one input ofthe comparator 116 through a conductor 118.

To maintain synchronism with the 60 hertz mains power, the other inputof comparator 116 is connected to the output of conductor 88 from whichit receives a 60 hertz signal from the AC source 82. The output of thecomparator 116 is applied to the input of the low pass filter 119 whichconverts it to a DC potential having an amplitude related to thefrequency difference between the signals on conductors 118 and 88 andapplies it to the input of the VCO 108. The components of the phaselocked loop 86 are selected so that when the comparator 116 is receivingthe same frequency on conductors 88 and 118, the VCO 108 applies 960hertz pulses (16 times the mains frequency) to the conductor 94.

While FIG. 3 shows one type of phase locked loop with dividers toprovide frequencies which are desirable in this circuit, other designsof phase locked loops are available for use in a similar manner.

In FIG. 4, there is shown a simplified logic diagram of the sensorinput-output circuit 96 having a sensor output timing circuit 120 and asensor input timing circuit 122. The sensor output timing circuit 120receives video signals from the sensor 18 on conductor 100B andend-of-readout signals on conductor 100A and applies the videoinformation to the display 16 on conductor 102; the sensor input timingcircuit 122 receives clock pulses on conductor 92 from the phase lockedloop 86 (FIGS. 2 and 3) and provides a start readout signal on conductor98A, a first phase readout signal on conductor 98B and a second phasereadout signal on conductor 98C to the sensor 18. The sensor inputtiming circuit 122 and sensor output timing circuit 120 are electricallyconnected by conductors 124 and 126.

To read information from the scanning sensor 18 to the display 16, thesensor output timing circuit 120 includes an amplifier stage 128, a NANDgate 130, a flip-flop 132, a NOR gate 134, and an NPN transistor 136connected in series in the order named. The input to the amplifier 128is connected to conductor 100B to receive the output from the scanningsensor 18.

The NAND gate 130, the flip-flop 132 and the NOR gate 134 are connectedin series to synchronize the readout and convert blocked photocellsignals to binary ones at the output of NOR gate 134 and binary zero(ground level) at conductor 102.

The synchronization of the signals is necessary because, in thepreferred embodiment, the photocells of the sensor integrate the signalrepresenting the light passing the object and then are read out rapidlyin synchronism with signals of alternate phase. Accordingly, the videosignals from the scanning sensor are read out over a short period oftime between start and stop pulses.

The converting of the blocked photocell signals to binary zero pulses at102 is necessary because the photocells blocked by the object provide asteady binary zero output that shows no separation between photocellswhereas it is desirable to count binary zero pulses (ground level atoutput of the scanner at 100B and ground level at 102) for thosephotocells, one pulse for each blocked photocell.

The video signals may also vary in width, principally because of edgeeffects of the objects being measured. However, it is desirable toprovide constant width pulses to the display counter or other devicesthrough conductor 102.

To develop constant width pulses from the video signals which may varyin width, NAND gate 130 has one of its two inputs electrically connectedto the output of the amplifier 128 through conductor 129 and its otherinput electrically connected to conductor 124. With this connection, theNAND gate 130 receives a low (binary zero) signals before the beginningof each readout of the sensor 18 from conductor 124 on one of its twoinputs. This puts the flip-flop 132 in an initial condition such thatits Q output is high. The NAND gate 130 receives video signals on theother of its inputs from the output of the video amplifier 128 duringthe readout of the sensor so that binary zero pulses from the output ofthe video amplifier 128 during the readout result in a binary one beingapplied to the set terminal of the flip-flop 132. This signal carriesbinary zero pulses which correspond to elements that were not blockedfrom light and thus accumulated charge.

To synchronize the video signals, the clock terminal of the flip-flop132 is electrically connected to conductor 138 which carries gated clockpulses. These gated clock pulses reset the flip-flop 132 so that itprovides a binary zero on its Q output terminal since its data input isa binary zero. A binary zero output pulse from video amplifier 128,which corresponds to an element of sensor 18 (FIG. 2) that was exposedto light sets flip-flop 132 so as to change its Q output to a binaryone.

One of the inputs of the NOR gate 134 is connected to the Q output ofthe flip-flop 132 through conductor 133 and the other is connected toconductor 138 so that pulses are applied to the output of the NOR gate134 if the flip-flop 132 has not been set by the video signalcorresponding to an element of the sensor that was exposed to light. Ifthe flip-flop 132 has been set thus causing the Q output to go high,there will be no pulse on the output of NOR gate 134. Before thebeginning of the readout of the sensor, flip-flop 132 is set by a binaryzero pulse on conductor 124 from flip-flop 156 and the resulting setpulse from NAND gate 130. This initially prevents clock pulses frompassing through gate 134. Since the output of the NOR gate 134 isconnected to the base of the NPN transistor 136 through conductor 135,the collector of the NPN transistor 136, which is in a grounded emitterconfiguration, provides binary zero pulses for each element of thescanning sensor that has not been exposed to light since flip-flop 132has not been set.

To provide gated clock pulses and an end-of-scan signal, the sensoroutput timing circuit 120 includes a flip-flop 140, a NOR gate 142, aninverter 144, a second flip-flop 146, and an NPN transistor 148.

The flip-flop 140 has its clock input terminal electrically connected tothe conductor 124 and its reset input terminal electrically connected tothe Q bar output (sometimes referred to as not Q or Q) of the flip-flop146 through conductor 147. Its Q bar output is electrically connected toconductor 141 and to one of two inputs of the NOR gate 142, the otherinput being connected to conductor 126 and the output of NOR gate 142being connected to conductor 138 through the inverter 144.

The data and non-reset inputs (activated by binary low, expressedsometimes as reset bar) of the flip-flop 146 are electrically connectedto the collector of the NPN transistor 148, the base of which iselectrically connected to conductor 100A, and the clock input of theflip-flop 146 is connected to conductor 126. The emitter of the NPNtransistor 148 is connected to ground.

With these connections, a low signal is applied from the Q bar output ofthe flip-flop 140 to one input of NOR gate 142 through conductor 141 atthe beginning of each readout because of the end of the binary zeropulse applied to the clock input of flip-flop 140 by conductor 124; andclock pulses from conductor 126 are applied to the other of the twoinputs of the NOR gate 142. The pulses applied to NOR gate 142 result ingated clock pulses being applied to the flip-flop 132 and to one inputof the NOR gate 134 through inverter 144.

At the end of a readout from the scanning sensor 18, an end-of readoutpulse is applied to conductor 100A and drives the transistor 148 intoconduction. Transistor 148 applies a negative going potential to thereset bar input of the flip-flop 146 which is then reset and thus resetsthe flip-flop 140. When flip-flop 140 is reset the clock pulses areterminated by a positive signal from the flip-flop 140 to one input ofthe NOR gate 142.

Although one amplifier 128 is shown in FIG. 4, for purposes ofillustration, more than one amplifier may be used. For example, in thepreferred embodiment, the scanning sensor is a Reticon scanner whichrequires an operational amplifier connected as a current-to-voltageamplifier, and a voltage comparator. The video signal is compared to avoltage signal level that can be adjusted by a potentiometer in thiscircuit to make a fine adjustment to set threshold of the comparatorbetween binary one (negative) and a binary zero (near ground at 100B)and thus compensate for certain types of noise and variations such asvariations in intensity of light from the light source, nonlinearity ofthe sensor and the like.

To provide timing signals to the scanning sensor 18 and clock pulses tothe sensor output timing circuit on conductor 126, the sensor inputtiming circuit 122 includes a clock pulse generator 150, 5 flip-flops,152, 154, 156, 158 and 160, a NAND gate 162, a buffer 164, and atransistor 166.

To provide the basic timing signals, the clock pulse generator 150generates 200 kilohertz clock pulses and applies them through conductor168 to the clock terminal of flip-flop 152, the clock terminal offlip-flop 154, conductor 126, the clock terminal of flip-flop 158, andthe clock terminal of flip-flop 160. Conductor 92 applies 240 hertzpulses to the data-in and to the set terminals of flip-flop 152, withflip-flop 152 having its Q output electrically connected to the data-inand to the set terminals of flip-flop 154 and its Q bar output terminalconnected through conductor 155 to one of the two inputs of NAND gate162, the other input being connected to the Q output terminal offlip-flop 154.

With these connections, the NAND gate 162 applies negative pulses toreset the flip-flop 156, to set the flip-flop 160, and to reset theflip-flop 158. These pulses occur at a rate of 240 hertz but aresynchronized by flip-flops 152 and 154 to coincide with the positivetransitions of the continuously running clock 150. Flip-flop 158 appliesset pulses to flip-flop 156 and data pulses to flip-flop 160, theflip-flop 160 applying data pulses to flip-flop 158. The Q outputs offlip-flop 158 and flip-flop 160 are applied to terminals 98C and 98Brespectively to provide two phase signals at 100 kilohertz. The Q-baroutput of flip-flop 156 is connected to the base of the PNP transistor166 to apply a negative pulse to output conductor 98A during the startof a scan. The Q output of flip-flop 156 provides a negative pulse onconductor 124 which occurs before the read-out of the sensor occurs.

In FIG. 5, there is shown a block diagram of the display 16 including aninput switch 170, an object-size adjustment counter 172, a readoutcounter section 174, a zero blanking and multiplex circuit 176, aplurality of digit displays 178A-178D and a segment driver section 180.

The readout counter section 174 receives pulses from the scanning sensor18 on conductor 102 through the input switch 170. It has a sufficientnumber of bits to provide a plurality of one digit indications of areaand has its outputs connected to: (1) the zero blanking and multiplexcircuit 176 through conductors 175A-175D which carry BCD signals toindicate the value in each digit position; and (2) to the digit displays178 through conductors 183A-183D to select the digit for display duringmultiplexing. The driver section 180 is connected to the zero blankingand multiplex circuit 176 through conductors 214 and 181A-181C and tothe segments of the digit displays 178A-178D and energizes selected onesof the segments in synchronism with signals from the readout countersection 174 to energize the selected segments at the time the selecteddigit display 178 is energized.

To adjust the decimal point of the digit display to accommodate itemsbetween the 7.62 centimeter guides or the 25.4 centimeter guides asshown on FIG. 1, the size-adjustment switch 170 includes a movableswitch arm 182, a first stationary contact 184, and a secondarystationary contact 186.

Conductor 102 is electrically connected to stationary contact 186 and tothe count input terminal of the size-adjustment counter 172, which is athree position counter. The third output of the counter is electricallyconnected to stationary contact 184 and to the reset terminal of thecounter 172 so that the counter 172 recirculates every third count. Theswitch arm 182 is electrically connected to the count input of the firststage of the counter 174 so that, with the switch arm 182 in contactwith stationary contact 186, each of the pulses from conductor 102 iscounted by the counter 174 and with the switch arm 182 closed instationary contact 184, every third count of the counter 172 is countedby the counter 174.

To adjust the readout counter 174 to the proper digit, the three countersections 174A, 174B and 174C of the readout counter 174 are connected inseries in the order named with section 174A receiving the count fromswitch 170 and section 174C being the last section. The number of stagesin section 174A which are counted for each pulse applied to section 174Bis selected to provide the desired scaling factor to section 174B toindicate a digit representing the dimension of the object beingmeasured.

In the preferred embodiment, since the readout is in millimeters and thecounts are also in millimeters when the switch 170 is properly adjusted,the counter 174A is not necessary and can be left out of the circuit sothat the counts are applied directly to section 174B. However, for otherdimensions, section 174B has its input connected to a selected tap ofsection 174A to accommodate different dimensions. For different unitssuch as inches, the speed of the belt must also be changed to adjust thenumber of counts for the area being measured in the direction of motionas well as the change made in counter section 174A for the dimensionperpendicular to the direction of motion.

The zero blanking and multiplex circuit 176 is electrically connected toconductor 94 to receive 960 hertz pulses from the phase locked loop 86(FIGS. 2 and 3) for synchronizing and to sections 191A and 191B throughconductors 198 and 200, respectively to multiplex the illumination ofnumbers in the display device by energizing alternate sections 191A and191B of the digit select multiplex circuit.

To energize selected numerals to the digit displays 178A-178D, the zeroblanking and multiplex circuit 176 is connected to the driver section180, which includes the seven segment drivers 185, through conductors181A-181C. The seven segment drivers 185 are electrically connected toeach of the segments in the digit displays 178A-178D through conductors189A-189C. The decimal driver 187 of the driver section 180 iselectrically connected to conductor 214 to receive signals from the zeroblanking and multiplex circuit 176 indicating the particular decimal tobe illuminated.

Each of the seven segments represents a certain value in each digitdisplay and is connected through a different one of the conductors189A-189C to a seven segment driver and to the segments representing thesame value in the other digit displays so that a signal is applied toeach digit display indicating the numeral represented by that value. Thedecimal driver 187 is connected to the decimal point segments of alldigit displays through conductors to apply signals indicating theselected decimal point location.

To select the digit display to show the numeral and decimal pointselected by the driver section 180, the readout counter section 174includes the digit select multiplex circuits 191A and 191B and thedrivers 193A-193D which sequentially energize the digit display178A-178D at the same time the selected values are transmitted to thezero blanking and multiplex circuit in BCD code over conductors175A-175D.

Since the drivers are energized in sequence starting with the mostsignificant bit position, the digit displays 178A-178D receive digits insequence from the counter sections 174B and 174C so as to start with themost significant bit position and move to the least significant digitsas the sequence progresses. The drivers 193A-193D energize the commonconductor of the digit displays in response to energization by the digitselect multiplex circuits 191A and 191B.

To reset the counters 174A-174C after a measurement, a manual resetswitch (not shown) which connects a reset pulse to conductor 195 isprovided. In the alternative, a pulse generator which generates resetpulses for every complete revolution of the conveyor belts can be used.Conductor 195 is connected to the reset terminal of counters 174A-174C.

To blank zeros, the output conductors 175A-175D are connected to thezero blanking and multiplex circuit 176. The zero blanking and multiplexcircuit 176 detects a zero numeral indication being provided to a digitdisplay and applies a signal to the driver corresponding to that displayto prevent the energization of the display.

While four drivers and digit displays are shown in FIG. 5 it isunderstood more may be used, and in the preferred embodiment, eight areused. Moreover, the correct number of conductors is not shown in thisdescription but a sample number, such as three, conveniently used inplaces for illustration only.

The decimal point in the display may be changed to provide moresignificant numbers when the different sizes are changed. This change ismade in the zero blanking multiplex circuit 176 and merely requires theshifting of a switch 202 (not shown in FIG. 5) within the zero blankingand multiplex circuit 176 which changes the timing of a pulse onconductor 214 to the decimal driver 187.

In FIG. 6, there is shown a logic circuit diagram of the zero blankingand multiplex circuit 176 having a ring counter 188, a multiplex logiccircuit 190, BCD to 7 segment decoder with blanking circuit 192, a NORgate logic circuit 204 and an OR gate logic circuit 206.

The multiplex logic circuit 190 includes two NOR gates 194 and 196 eachhaving one input connected to a different output terminal of the counter188 and the other input connected to an output of the other of the twoNOR gates so as to form a flip-flop. During counting operations, theflip-flop is switched from stage to stage to provide alternate phasepulses on counter-select output conductors 198 and 200, each of which isconnected to a different one of the digit select multiplexers 191A and191B to provide multiplexing of the two counters.

The zero blanking circuit includes a single-pole, double-throw switch202, a NOR gate logic circuit 204 and an OR gate logic circuit 206.

To adjust for different size items or to change the decimal point, theswitch 202 includes a first stationary contact 208, a second stationarycontact 210, and a movable switch arm 212, with each of the stationarycontacts 208 and 210 being connected to different outputs of the counter188 and the movable switch arm 212 being electrically connected to aconductor 214. With this arrangement, the conductor 214 may be connectedto either of the two outputs, one of which is for smaller sizemeasurements and the other for larger sizes. To adjust to differentunits the output conductors of the ring counter 188 to which switchcontacts 208 and 210 are connected are changed. Thus, this circuitprovides a counting means for dividing the pulses applied to counter 188by a selected number to adjust for different size items being measured.

The means for dividing includes a means for dividing substantially inaccordance with the square of the factor by which the dimension of theimage focused on the sensing means is changed in a directionperpendicular to the direction of motion of the measuring means andobject with respect to each other. For example, as described above inthe preferred embodiment the lens may be changed to focus between awidth along the conveyor of 25.4 centimeters (10 inches) or between awidth of 7.62 centimeters (3 inches). Thus the factor by which thedimension of the image focused on the sensing means is changed in adirection perpendicular to the direction of motion of the conveyor isthree. The square of three is nine and so the dividing means, which isdescribed above as the ring counter 188, divides by nine in the usualmanner, providing one output for every nine counts around the ringcounter in a conventional manner for dividing with ring counters.

To blank zeros, the OR gate circuit 206 includes four OR gates 216A,216B, 218 and 222. OR gates 216A and 216B have their inputs connected toBCD outputs of counter sections 174B and 174C through conductors175A-175D, which designate the numeral read into the counters torecognize a zero count in those sections. Conductors 175A-175D are alsoconnected to the BCD to seven segment decoder with blanking 192 fordecoding of the BCD to a seven segment code with the conductor for eachsegment being energized at its proper count for application toconductors 181A-181E. The outputs of OR gates 216A and 216B are eachconnected to a different one of the two inputs of the OR gate 218, theoutput of which is connected to one of the two inputs of OR gate 222.The other input of OR gate 222 is connected to conductor 214 torecognize a digit to the left of the decimal point.

The NOR gate circuit 204 includes first and second NOR gates 224 and 226connected together as a flip-flop with the output of each beingconnected to one of the two inputs of the other. The other input of theNOR gate 226 is connected to an output of counter 188 and the otherinput of the NOR gate 224 is electrically connected to the output of ORgate 222, so that, during the multiplexing operation, the recognition ofa non-zero digit or the digit to the left of the decimal point in eitherof the sections 174B or 174C causes the flip-flop to be set to apply apulse to output conductor 228 of the NOR gate 226, thus causing the BCDto seven segment decoder with blanking 192 to discontinue to blank itsoutputs at that digit and subsequent less significant digits.

The BCD to seven segment decoder with blanking 192 converts the BCD codereceived on conductors 175A-175D to a signal on one of the conductors181A-181E corresponding to the numeral indicated by the BCD code fromthe counters 174B and 174C. This indication is applied to the sevensegment drivers 185 (FIG. 5) together with the decimal drive signal onconductor 214 in synchronism with the signals applied to the selecteddigit display 178A-178D (FIG. 5) from the drivers 183A-183D. A blankingsignal on conductor 228 blocks the signals to the segments.

In FIG. 7, there is shown a schematic circuit diagram of the fluorescentlamp drive circuit 104 and the fluorescent lamp 20.

To apply alternating potentials to the fluorescent lamp 20, thefluorescent lamp drive circuit 104 includes first and second half-wavedrivers 230A and 230B, which are identical in construction. Half-wavedriver 230A is electrically connected to input conductors 232A and 234Aand output conductor 236A; half-wave driver 230B similarly is connectedto input conductors 232B and 234B and output conductor 236B. Thehalf-wave driver 230A will be described in detail but not the half-wavedriver 230B since its parts are identical and are numbered withreference numerals differing only by the suffix from those used in theexplanation of driver 230A.

The half-wave driver 230A includes a NOR gate 238A, an amplifier 240A, aDarlington amplifier (NPN transistor 242A and NPN transistor 244A), aresistor 246A, and an NPN transistor 248A connected in series in theorder named. The NOR gate 238A has one of its two inputs electricallyconnected to conductor 232A and its other input electrically connectedto conductor 234A. The collector of output transistor 248A iselectrically connected to: (1) conductor 236A so that two binary zeroinputs to the NOR gate 238A result in a half-wave output on conductor236A; and (2) an over-voltage short circuit 282 through a conductor 262to protect against high voltage transients.

The transistor 248A is protected by a transistor circuit including NPNtransistor 250A and 252A. In this circuit, the input of the amplifier240A is directly connected to the output of the NOR gate 238A and theoutput of the amplifier 240A is connected to the base of the transistor242A, the collector of which is connected to: (1) the collector oftransistor 250A; (2) the source of positive potential 251; and (3)ground through the series connected resistor 254A and capacitor 256A.

Between ground and the capacitor 256A, another resistor 258A has one endconnected to ground and its other end connected to the base of thetransistor 250A. The collectors of the transistors 242A and 244A formingthe Darlington amplifier are electrically connected to the collector ofthe transistor 250A and transistor 244A has its emitter connectedthrough the resistor 246A to the base of transistor 248A.

To protect against excessive dissipation due to unsaturated operation oftransistor 248A, transistor 252A has its collector electricallyconnected to the base of the transistor 248A, its emitter electricallyconnected to ground and to the emitter of the transistor 248A and itsbase electrically connected to the emitter of transistor 250A through aresistor 260A. A point 264A in the circuit is electrically connected to:(1) conductor 262 through the forward resistance of a diode 266A; (2) tothe base of transistor 250A through the forward resistances of diodes268A and 270A; (3) to the emitter of transistor 244A through the forwardresistance of a diode 272A; and (4) to ground through the forwardresistance of the diode 272A and a resistor 274A.

In a similar manner, the half-wave driver 230B has: (1) one input of theNOR gate 238B electrically connected to conductor 232B; (2) its otherinput electrically connected to conductor 234B; and (3) the collector ofa transistor 248B is electrically connected to output conductor 236B andto a circuit 282 through a conductor 276.

To start and run the fluorescent lamp 20, the fluorescent lamp drivecircuit 104 includes first, second and third switches 276, 278 and 279,an inverter 280, the over voltage circuit 282, a transformer 284 and aresistor 286.

The inverter 280 has its output electrically connected to conductor 232Band its input electrically connected to conductor 90 (FIGS. 3 and 7) andconductor 232A so that positive pulses on conductor 90 are applieddirectly to NOR gate 238A, are inverted by inverter 280 and applied as anegative pulse to NOR gate 238B. Similarly, negative pulses applied toconductor 90 are applied directly to NOR gate 238A and inverted beforebeing applied to NOR gate 238B. With this arrangement, the NOR gate 238Aand the NOR gate 238B are alternately energized to provide alternatingpulses to the fluorescent lamp 20.

The switch 276 is a single-pole, double-throw switch having a moveableswitch arm 288, a first stationary contact 290, and a second stationarycontact 292, with the second stationary contact 292 being electricallyconnected to a source of positive potential 294 and the first stationarycontact 290 being electrically grounded at 296.

With these connections, the switch arm 288 is in contact with stationarycontact 290 when the circuit is in the run position. In this position aground level pulse is applied to one input of both the NOR gate 238A andthe NOR gate 238B so that, when a negative or ground level pulse (binaryzero) is applied to the other input of either of these gates, a positiveoutput (binary one) is provided by the NOR gate 238B and when a positiveinput is provided to either NOR gate 238A or NOR gate 238B that gateprovides a negative output.

When the switch arm 288 is against the second stationary contact 292,the circuit is off and a negative pulse is applied by the output of NORgate 238B and 238A. Accordingly, with the switch in the run position,the drivers 230A and 230B alternately provides output pulses toconductors 236A and 236B and when off neither provides output pulses.

The primary winding of transformer 284 has one end electricallyconnected to conductor 236A, the other end connected to conductor 236Band its center tap connected to the positive source of 16 volts so as totransmit alternating pulses to its secondary winding. The circuit 282includes a first diode 298 having its anode electrically connected toconductor 262 and its cathode connected to ground through the reverseresistance of the zener diode 300 and a second diode 302 having itsanode electrically connected to conductor 276 and its cathodeelectrically connected to ground through the reverse resistance of thezener diode 300.

The secondary winding of the transformer 284 has one end electricallyconnected to one of the electrodes of the fluorescent lamp 20 throughthe resistor 286 and its other end electrically connected to ground andto the other electrode of the fluorescent lamp 20. With theseconnections, when the lamp is in running condition, alternating currentpulses are applied across the lamp 20 which causes it to emit flickeringlight at the frequency of the pulses applied to it.

The switch 278 is a single-pole, single-throw switch having its moveableswitch arm 304 electrically connected to a source of positive potential306 and having a stationary contact 308 electrically connected to theresistor 286 and to the first electrode of the fluorescent lamp 20. Theswitch 279 is also a single-pole, single-throw switch having its switcharm 277 electrically connected to one of the electrodes of thefluorescent lamp 20 and a stationary contact 310 electrically connectedto the other electrodes.

With these connections, the fluorescent lamp may be started by closingmoveable switch arm 288 against contact 292 to prevent NOR gates 238Aand 238B from applying pulses to the inverters 240A and 240B, thuspreventing alternating current from being applied to the secondary ofthe transformer.

With the switches 278 and 279 closed, which is the start position forthe fluorescent lamp 20, current flows from the source 306 through theswitch arm 304, the contact 308, the first electrode of the lamp 20, thefixed contact 310, the switch arm 277, through the second electrode ofthe fluorescent lamp 20, and to ground to heat those electrodes beforepulses are applied. Current also flows through the resistor 286 and thesecondary winding of transformer 284 to ground to store energy in theinductive field of the secondary winding.

When the switches 278 and 279 are switched open and switch 276 switchedto the run position, alternating current pulses are applied to theprimary of the transformer and the secondary is discharged through thefluorescent lamp 20, thus providing a high start potential followed byalternating pulses. In this manner, the secondary of the transformer 284acts as a ballast.

From the above description, it can be understood that the area meter 10has several advantages, such as: (1) it is inexpensive to build; (2) itis adjustable to measure different area objects while retaining goodresolution with each size; (3) it is adjustable to align the belts ofthe conveyor in such a manner as to reduce the travel from one side tothe other; and (4) it may handle thick or thin objects withoutdifficulty.

It is economical to build because synchronism is obtained by the use ofa phase locked loop operated from the same source that drives thesynchronous motor of the belt system rather than by relatively expensivemechanical systems. The phase locked loop generates pulses insynchronism with the belt and these pulses are used to control the rateof scanning by the Reticon scanner tube and to cause the fluorescentlamp to flicker at a rate sufficiently high to preserve good video.

It has the advantage of being adjustable to different sizes withrelative ease because the scan rates can be adjusted by changing thelens and making a minor adjustment in the counter. By changing thedecimal point of the readout, a sufficient number of significant digitsis maintained in the readout.

Each end of the rollers of the belts can be adjusted to align the beltso there is no travel from one side to the other. A pivotable idlerwhich moves both top and bottom runs of the top conveyor belt upwardlyto permit large objects to pass underneath it prevents the belts frombeing distorted by such large objects and from slipping on the rollers.

Although a preferred embodiment has been described with someparticularity, many modifications and variations in the embodiment arepossible without deviating from the invention. It is, therefore, to beunderstood that within the scope of the appended claims, the inventionmay be practiced other than as specifically described.

What is claimed is:
 1. Apparatus comprising:measuring means forgenerating a plurality of area pulses related to the area of an objectto be measured; conveyor means for moving the object to be measured andthe measuring means with respect to each other; said measuring meansincluding sensing means for generating a plurality of dimension pulsesproportional to at least one dimension of said object to be measured andfocusing means for focusing an image of at least a portion of saidobject to be measured onto the sensing means; said focusing meansincluding replaceable means for focusing different sizes of saidportions of said object across a predetermined length of said sensingmeans; said measuring means further including counting means forcounting said pulses, whereby said counted pulses provide an indicationof said area of said object; said counting means including means fordividing said count by a predetermined number, whereby said area of saidobject is accurately represented even though said image is changed insize; said conveyor means for moving the object and measuring means withrespect to each other includes a conveyor and means for moving saidconveyor; said means for moving said conveyor includes a synchronousmotor and alternating current means for applying power to saidsynchronous motor; said measuring means includes pulse means forgenerating basic-timing pulses proportional to the rate at which saidobject is moved with respect to said measuring means; and said pulsemeans includes phase locked loop means for generating basic-timingpulses in synchronism with said alternating current from saidalternating current means.
 2. Apparatus comprising:measuring means forgenerating a plurality of area pulses related to the area of an objectto be measured; conveyor means for moving the object to be measured andthe measuring means with respect to each other; said measuring meansincluding sensing means for generating a plurality of dimension pulsesproportional to at least one dimension of said object to be measured andfocusing means for focusing an image of at least a portion of saidobject to be measured onto the sensing means; said focusing meansincluding replaceable means for focusing different sizes of saidportions of said object across a predetermined length of said sensingmeans; said measuring means further including counting means forcounting said pulses, whereby said counted pulses provide an indicationof said area of said object; said counting means including means fordividing said count by a predetermined number, whereby said area of saidobject is accurately represented even though said image is changed insize; and said means for dividing including means for dividingsubstantially in accordance with the square of the factor by which thedimension of the image focused on the sensing means is changed in adirection perpendicular to the direction of motion of the measuringmeans and object with respect to each other.
 3. Apparatuscomprising:measuring means for generating a plurality of area pulsesrelated to the area of an object to be measured; conveyor means havingan adjustable bite for moving the object to be measured and themeasuring means with respect to each other; said measuring meansincluding sensing means for generating a plurality of dimension pulsesproportional to at least one dimension of said object to be measured andpulse means for generating basic-timing pulses proportional to the rateat which said object is moved with respect to said measuring means; saidconveyor means including first and second endless belts adjacent to eachother; said first and second endless belts each including top and bottomruns; a feed path between said first and second endless belts; means fordriving said first and second endless belts so that the bottom run ofthe first belt moves at the same speed and against the top run of thesecond belt; said belts including a plurality of belt rollers, each ofsaid belt rollers being adjustable in angle on each of its ends; saidtop belt including an idler roller assembly; said idler roller assemblyincluding first and second rollers; said first and second rollers havingtheir outer rims spaced a distance from each other equivalent to thedistance between the top and bottom runs of said top belt and greaterthan the diameter of said belt rollers; said bottom roller of saidassembly being against the top of the bottom run and the top rollerbeing against the bottom of the top run; and means for pivoting said topand bottom idler rollers with respect to a point removed from themwhereby an object lifting the bottom run of said top conveyor moves saididler assembly upwardly and causes the top run of said conveyor to belifted by the top idler roller.
 4. Apparatus comprising:measuring meansfor generating a plurality of area pulses related to the area of anobject to be measured; conveyor means for moving the object to bemeasured and the measuring means with respect to each other; saidmeasuring means further including counting means for counting saidpulses; said measuring means further including means for changing therelationship between the number of said area pulses and the area of saidobject; said counting means including means for dividing said count by apredetermined number, whereby said area of said object is accuratelyrepresented even though said relationship is changed; said measuringmeans includes pulse means for generating basic-timing pulsesproportional to the rate at which said object is moved with respect tosaid measuring means; said conveyor means including a synchronous motorand alternating current means for applying power to said synchronousmotor; said pulse means including phase locked loop means for generatingbasic-timing pulses in synchronism with alternating current from saidlaternating current means; and said measuring means further including afluorescent lamp; drive means for driving said fluorescent lamp; andmeans for driving said drive means in synchronism with said basic-timingpulses from said phase locked loop.
 5. Apparatus according to claim 4 inwhich:said fluorescent lamp includes a means for starting said lamp;said means for starting said lamp including a transformer, and a switchmeans for causing DC current to flow through said transformer prior toapplying said alternating drive current and for breaking said DC circuitand causing said field of said transformer to apply energy across thefluorescent lamp prior to applying said alternating current. 6.Apparatus in accordance with claim 5 further including:display means fordisplaying said measurement; and said display means including means forshifting the decimal point in said measurement.
 7. Apparatuscomprising:measuring means for generating a plurality of area pulsesrelated to the area of an object to be measured; conveyor means formoving the object to be measured and the measuring means with respect toeach other; said measuring means including sensing means for generatinga plurality of dimension pulses proportional to at least one dimensionof said object to be measured and pulse means for generatingbasic-timing pulses proportional to the rate at which said object ismoved with respect to said measuring means; said means for moving theobject and measuring means with respect to each other including motormeans for moving said object and measuring means with respect to eachother in proportion to alternating current applied to said motor means;and said pulse means and sensing means including phase locked loop meansfor generating said basic-timing pulses with a repetition rateproportional to the frequency of said alternating current.
 8. Apparatusaccording to claim 7 in which said measuring means further includescounting means for counting said area pulses.
 9. Apparatus according toclaim 7 in which:said measuring means includes a fluorescent lamp; drivemeans for driving said fluorescent lamp; and means for driving saiddrive means in synchronism with pulses from said phase locked loop. 10.Apparatus according to claim 9 in which:said fluorescent lamp includes ameans for starting said lamp; said means for starting said lampincluding a transformer, and a switch means for causing DC current toflow through said transformer prior to applying said alternating drivecurrent and for breaking said DC circuit and causing said field of saidtransformer to apply energy across the fluorescent lamp prior toapplying said alternating current.
 11. Apparatus in accordance withclaim 7 further including:display means for displaying said measurement;and said display means including means for shifting the decimal point insaid measurement.
 12. Apparatus comprising:measuring means forgenerating a plurality of area pulses related to the area of an objectto be measured; conveyor means for moving the object to be measured andthe measuring means with respect to each other; said measuring meansfurther including counting means for counting said pulses; saidmeasuring means further including means for changing the relationshipbetween the number of said area pulses and the area of said object; saidcounting means including means for dividing said count by apredetermined number, whereby said area of said object is accuratelyrepresented even though said relationship is changed; said measuringmeans including a sensing means for generating pulses representing atleast one dimension of said object to be measured; means for focusing animage of said object to be measured onto said sensing means; and saidmeans for dividing including means for dividing substantially inaccordance with the square of the factor by which the dimension of theimage focused on the sensing means is changed by said focusing means ina direction perpendicular to the direction of motion of the measuringmeans and object with respect to each other.
 13. Apparatus according toclaim 12 in which said conveyor means includes a plurality of belts anda plurality of belt rollers, each of said belt rollers being adjustablein angle on each of its ends.
 14. Apparatus according to claim 13 inwhich:said belts comprise a top belt having top and bottom runs and abottom belt; said top belt includes an idler roller assembly; said idlerroller assembly including first and second rollers; said first andsecond rollers having their outer rims spaced a distance from each otherequivalent to the distance between the top and bottom runs of said topbelt and greater than the diameter of said rollers; said bottom rollerof said assembly being against the top of the bottom run and the toproller being against the bottom of the top run; means for pivoting saidtop and bottom idler rollers with respect to a point removed from themwhereby an object lifting the bottom run of said top conveyor moves saididler assembly upwardly and causes the top run of said conveyor to belifted by the top idler roller.
 15. Apparatus comprising:measuring meansfor generating a plurality of area pulses related to the area of anobject to be measured; conveyor means for moving the object to bemeasured and the measuring means with respect to each other; saidmeasuring means further including counting means for counting saidpulses; said measuring means further including means for changing therelationship between the number of said area pulses and the area of saidobject; said counting means including means for dividing said count by apredetermined number, whereby said area of said object is accuratelyrepresented even though said relationship is changed; said measuringmeans including a sensing means for generating pulses representing atleast one dimension of said object to be measured; means for focusing animage of said object to be measured onto said sensing means; said meansfor dividing including means for dividing substantially in accordancewith the square of the factor by which the dimension of the imagefocused on the sensing means is changed by said focusing means in adirection perpendicular to the direction of motion of the measuringmeans and object with respect to each other; said conveyor meansincluding a plurality of said belts and a plurality of belt rollers,each of said belt rollers being adjustable in angle on each of its ends;said belts comprising a top belt having top and bottom runs and a bottombelt; said top belt including an idler roller assembly; said idlerroller assembly including first and second rollers; said first andsecond rollers having their outer rims spaced a distance from each otherequivalent to the distance between the top and bottom runs of said topbelt and greater than the diameter of said rollers; said bottom rollerof said assembly being against the top of the bottom run and the toproller being against the bottom of the top run; means for pivoting saidtop and bottom idler rollers with respect to a point removed from themwhereby an object lifting the bottom run of said top conveyor moves saididler assembly upwardly and causes the top run of said conveyor to belifted by the top idler roller; said measuring means including afluorescent lamp; drive means for driving said fluorescent lamp; andmeans for driving said drive means in synchronism with pulses from saidphase locked loop.
 16. Apparatus comprising:measuring means forgenerating a plurality of pulses related to the area of an object to bemeasured; conveyor means having an adjustable bite for moving the objectto be measured and the measuring means with respect to each other; saidmeasuring means including sensing means for generating a plurality ofpulses proportional to at least one dimension of said object to bemeasured and pulse means for generating pulses proportional to the rateat which said object is moved with respect to said measuring means andcounting means for counting said pulses; said means for moving includingfirst and second endless belts adjacent to each other; said top andbottom endless belts each including top and bottom runs at least one ofwhich curves outwardly; a feed path between said first and secondendless belts; said means for driving including means for driving saidfirst and second endless belts so that the bottom run of the top beltmoves at the same speed and against the top run of the bottom belt; saidtop belt including an idler roller assembly; said idler roller assemblyincluding first and second rollers; said first and second rollers havingtheir outer rims spaced a distance from each other equivalent to thedistance between the top and bottom runs of said top belt where said onebelt is curved outwardly; said bottom roller of said assembly beingagainst the top of the bottom run and the top roller being against thebottom of the top run; and means for pivoting said top and bottom idlerrollers with respect to a point removed from them whereby an objectlifting the bottom run of said top conveyor moves said idler assemblyupwardly and causes the top run of the conveyor to be lifted by the topidler roller.
 17. Apparatus according to claim 10 in which said beltsinclude a plurality of rollers, each of said rollers being adjustable inangle on each of its ends.
 18. Apparatus according to claim 17 in whichsaid measuring means includes:means for providing pulses from saidsensing means proportional to said one dimension at time incrementsproportional to pulses, generated by said pulse means; and said onedimension being at an angle to the direction in which said object andmeasuring means are being moved with respect to each other. 19.Apparatus comprising:measuring means for generating a plurality ofpulses related to the area of an object to be measured; conveyor meanshaving an adjustable bite for moving the object to be measured and themeasuring means with respect to each other; said measuring meansincluding sensing means for generating a plurality of pulsesproportional to at least one dimension of said object to be measured andpulse means for generating pulses proportional to the rate at which saidobject is moved with respect to said measuring means and counting meansfor counting said pulses; said means for moving including first andsecond endless belts adjacent to each other; said top and bottom endlessbelts each including top and bottom runs at least one of which curvesoutwardly; a feed path between said first and second endless belts; saidmeans for driving including means for driving said first and secondendless belts so that the bottom run of the top belt moves at the samespeed and against the top run of the bottom belt; said top beltincluding an idler roller assembly; said idler roller assembly includingfirst and second rollers; said first and second rollers having theirouter rims spaced a distance from each other equivalent to the distancebetween the top and bottom runs of said top belt where said one belt iscurved outwardly; said bottom roller of said assembly being against thetop of the bottom run and the top roller being against the bottom of thetop run; means for pivoting said top and bottom idler rollers withrespect to a point removed from them whereby an object lifting thebottom run of said top conveyor moves said idler assembly upwardly andcauses the top run of the conveyor to be lifted by the top idler roller;said belts including a plurality of rollers, each of said rollers beingadjustable in angle on each of its ends; said measuring means includingmeans for providing pulses from said sensing means proportional to saidone dimension at time increments proportional to pulses, generated bysaid pulse means; said one dimension being at an angle to the directionin which said object and measuring means are being moved with respect toeach other; said means for moving the object and measuring means withrespect to each other includes a conveyor and means for moving saidconveyor; said means for moving said conveyor including a synchronousmotor and alternating current means for applying power to saidsynchronous motor; and said pulse means includes phase locked loop meansfor generating pulses in synchronism with said alternating current fromsaid alternating current means.
 20. Apparatus according to claim 19 inwhich:said measuring means includes a fluorescent lamp; drive means fordriving said fluorescent lamp; and means for driving said drive means insynchronism with pulses from said phase locked loop.